Utilization of relief printing presses for intaglio printing



Feb. 4, 1941. I H. A. w. WOOD 2,230,395

UTILIZATION OF RELIEF PRINTING PRESSES FOR INTAGLIO PRINTING Filed Jan. 24, 1939' Z"mpresai Z571 ress' (a /fade p Cylinder Patented F ch. 4, 1941 UNITED STATES PATENT OFFICE- UTILIZATION OF PRINTING PRESSES FOR IN'I'AGLIO PRINTING tion of Virginia Application January 24, 1939, Serial No. 252,580

1 Claim. (Cl. lob-157,)

This invention relates to the printing of magazines, magazine sections ofnewspapers, and the like.

' The principal objects of the invention are to 5 extend materially the field of what is called rotogravure printing? to bring into use numerous relief printing presses of various kinds and sizes, now idle for want of work and to put additional men to Work, without taking any work m away from those now occupied; to provide-for operating these relief presseswith intaglio cylinder's or plates at the full speed ofthese presses when printing from relief surfaces; and to provide a new and important way .of supplying ink to the printing surfaces of intaglio cylinders and plates, whereby the ordinary relief printing ma-' chines can be used without costly alterations.

Other objects and advantages of the invention will appear hereinafter.

Reference is to be had to the accompanying drawing, in which Fig. 1 is an end viewof a rotary relief printing press arranged in accordance with this invention;

Fig. 2 is an enlarged'view showing the doctor blade andthe guard plate for draining'excess ink on the ink cylinder; and f Fig. 3 is an end view indicating the application of this invention to a plate relief printing press but not showing the press in detail.

Of-recent years a new method of printing illustrated work has come into the printing art, particularly with respect to magazines and the magazine sections of newspapers.

35.. in the trade rotogravure printing. Technically,

it is spoken of as-being done from intaglio printing surfaces, which are engraved upon copper cylinders, the design being in intaglio and not'in relief. 7

40 -The films carrying the design, laid down on the copper surfaces of intaglio cylinders, have been photographed through a ruled screen comprising a network in which the .reticulations carry the design. .The design is composed on 5 the plate .of pockets which vary in superficial.

,per plates, which are smooth, and serve as a.

50 bearing for a doctor blade, beneath which .the cylinder rotatesin order that the blade may skive o the ink from its relieved or smooth portions.

ese relieved, smooth portions are in reality the walls between the indentations, wells, or pock 3s ets, which comprise the design. They have no This is called.

. functions in printing other than that of providing walls and a bearing upon which the doctor blade may bear and perform. its function of cleaning 05 the excess printing ink after the pockets, or wells, have been charged with ink. 5 These pockets have varying depths so that they may containa deeper or a shallower body of ink, the shallower body giving the lighter tones in color, while the heavier bodies give the darker tones. This, as I have said, is known as roto- 1o gravure printing.- a

Another, a somewhat like method of printing, consists in using reversed half-tones. Halftones usually carry relief printing surfaces. The design, which has been-pho'tographedthrough 15 a reticulated screen upon a plate, is comprised of the varying widths, of the relieved lines, which .in a:rotogravure plate are the walls which sep-' arate one well, or pocket, from another.

As in relief printing, the pockets, or wells, are 20 not printed from, but thetops of the separating walls are. No doctor blade is used for the removal of the ink that is carried by the tops of Both rotogravure and reversed ha1f-tone35 printing are known as intaglio printing because of sunken surfaces in the printing plate.

In both .of these methods the design carried by the cylindrical printing plate is rotatedin an ink fountain, which carries the printing pig- 0 ment. The plate picks up what pigment it needs and thereafter passes beneath a doctor blade.

This doctor blade skives off excess color so that only that which remains in its intaglio portions can be printed from, the excess ink going back into the fountain.

In intaglio printing there are two methods of applying the ink to the wells, or pockets, either by rotating the printing cylinder in a reservoir of ink as just described, or by flowing the ink against the design cylinder as it rotates, as by supply pipes or channels. In both of these methods the ink, having been put on in bulk, its excess must be removed before the memento! printing, and this is done by the doctor blade. ,85

usually of finely tempered steel, thin and elastic, which may be maintained carefully with respect to the smoothness of its working edge. Now I have discovered a new way of supplying ink to an intaglio printing surface by which intaglio plates may be run on ordinary relief printing presses and inked by means of the method of inking ordinarily used in relief printing and by the usual inking rollers of a relief printing press.

In a relief printing press the-ink is carried by a fountain, in which a roller rotates in the ink and carries out of the fountain an ink film of desired thickness, which is determined by a screwoperated fountain blade, usually of steel adjacent to the roller. As the fountain roller rotates with its ink, it comes into contact with what is known as a ductor roller. This roller picks up its supply of ink and transfers it to the ink distributing system of the press, which consists of a number of inking rollers of rubber, or "composition, which serve to spread it 'into a more even and;

thinner iilm'of ink until that film has been re-.

duced to the smooth and thin film of ink which it is desired to lay down upon the relief printing plate by form rollers."

Therefore, it will be seen that in relief printing, the surface of the printing plate governs and comprises the design which it itself prints, whereas in: intaglio printing the design is carried by the printing plate in a large number of minute wells, or pockets, which pockets carry the ink and form the design;

Now, I convert a relief printing press into an intaglio printing press by laying down the ink in the usual method useii in relief printing, by means of a fountain l I, fountain roll I l and rubber ductor roller l2, either with or without a distributing system intervening. I prefer to use at least an iron ink cylinder is and a rubber form roller ll. The latter supplies color to the entire surface of the intaglio plate It on the printing cylinder It, including the tops of its reticulated walls which form the desig as well as charging the design itself with ink and thereafter passing the printing cylinder l6 beneath a doctor blade H. The blade removes the ink from the surface of the walls, pressing and smoothing it into the wells between the walls, and leaving the intaglio surface charged with while the relieved wall surfaces are cleaned thereof. Thus, when it comes to the act of'printing between the printing cylinder II and the impression cylinder II, the

plate will be in the condition that an intaglio plate is normally, that is: its intaglio portions charged with ink audits relieved portions or walls of design cleansed thereof by the doctor blade. The ink removed by the doctor blade II is directed on to the ink cylinder" by means of a guide plate Ila. Thus, when such a plate goes to printing, it acts as an intaglio plate and not as a relief plate. In this manner intaglio plates may be printed upon relief printing machines and 'at the full speed thereof, a speed which it is not possible now to attain with intaglio printing machines.

Therefore, I need only enable relief presses, of which there are many in the world, to perform the functions of intaglio printing presses, of which there are but few, by the mere addition of doctor blades, which may be easily applied, working in conjunction with their printing cylinders, and the use of suitable printing inks.

While the chief application of this invention will be to rotary newspaper printing presses, printing from rolls of paper, it may be applied to rotary presses printing from sheets or to flat bed presses printing from fiat intaglio printing plates, with suitable provision for handling refuse ink scraped off from the printing plate.

In the form of relief press indicated in Fig. 3' the bed 20 carries a flat intaglio plate'2l and a doctor blade 22 is employed as in the other case.

I consider it of inestimable value to the printing trade that it should be enabled so easily to set to work upon a popular form of the printing art a great number of relief printing presses which are now idle because this new fashion of printing has come into vogue to which they have never been adapted. 4

Having thus described my invention and the advantages thereof, I do not wish to be limited to the details herein disclosed, otherwise than as set'forth in the claim, but what I claim is:

The combination in a rotary printing press, of an intaglio printing cylinder carried thereby, an ink foun a fountain roll in the ink fountain, a ductor"ro1ler arranged and adapted to remove ink from the fountain roll periodically, an ink cylinder on which the ductor roller deposits ink periodically, a form roller receiving ink from the ink cylinder continuously and depositing the ink in a thinned film on the printing cylinder, a doctor blade engaging-the printing cylinder, removing surplus ink from the printing cylinder, and smoothing the ink into the indentations therein, said doctor blade slanting downwardiyfrom the surface of the ink cylinder, and a guide plate in position toreceive the surplus ink removed by the doctor blade from the printing cylinder and direct the ink thus-taken up by the doctor blade back on to the surface of the ink cylinder.

. HENRY A. WISE WOOD. 

